Power semiconductor devices are used prevalently in power management applications, for example, power converters and power supplies. In many applications, efficiency of the power converter is strongly related to the efficiency of the power semiconductor device used therein. To obtain a higher efficiency, the current carrying capability of the semiconductor device must be improved which reduces its on resistance. To increase the current carrying capability of, for example, a trench type MOSgate device the pitch (the cell to cell distance) can be reduced. However, to reduce the pitch, the gate charge must also be reduced to reduce Qgd.
It is desirable to improve the current carrying capability of a power semiconductor device without having adverse effects on Qgd.